The invention relates to an ocular, such as binoculars or opera glasses.
Known binoculars and opera glasses must be held by hand before a user""s eyes. If the user cannot support his arms, it is not possible to keep the magnifying glass steady. This leads to a blurred picture seen by the user. In particular over an extended period of time holding of such magnifying glasses leads to exhaustion and thus to stronger shaking of the arms.
It is an object of the present invention to provide an easy-to-handle ocular which prevents the arms from exhausting.
The ocular according to the present invention comprises a magnifying device connected with a frame. Said magnifying device comprises at least two lenses per optical path. Thus at least two lenses are arranged in front of each human eye, the lenses magnifying the image viewed. The frame comprises a holding portion and a supporting portion. The holding portion is configured for holding the ocular on the human head and the supporting portion is configured for supporting the magnifying device.
Since the ocular according to the present invention is adapted to be directly fastened to the human head by means of the holding portion, it is no longer necessary that the user holds the ocular in his hands. Exhaustion of the arms caused by the force required to hold the ocular does not longer occur. The impression of a blurred image shown by known oculars is due to the fact that a relative movement takes place between the human eye and the ocular. Since the ocular according to the present invention is fastened to the human head by means of the holding portion, no relative movement takes place between the magnifying device and the human eye such that the user does not see a blurred image.
Further, the ocular according to the present invention offers the advantage that the user can move his head in any direction with the ocular following that movement. Another advantage is that the hands of the user are free.
The frame of the ocular according to the invention may be a kind of spectacle frame, wherein the holding portions serve as the spectacle sidepieces. Such a configuration allows the ocular to be easily put on and taken off like spectacles. The bridge of the spectacles, which corresponds to the supporting portion, may be provided with nose pads.
Preferably, the magnifying device is adapted to be fastened via an attachable fastening means to the supporting portion. Said fastening means can be provided on the magnifying device or the supporting means. Thus the magnifying device is adapted to be fastened by simple attachment to the supporting portion and removed by simple detachment from the supporting portion to allow transport of the ocular.
The fastening means are preferably configured as detachable snap-in means. This prevents unintended detachment of the magnifying device from the supporting means such that the magnifying device remains rigidly connected with the supporting means even in the event of stronger movements of the head.
To facilitate attachment of the magnifying device to and detachment of the magnifying device from the supporting portion, the fastening means preferably comprises at least one elastic fastening arm having a snap-in pin. When the magnifying device is attached or detached, the elastic arm is bent out of its initial position and returns to its initial position when the magnifying device has been completely attached to or completely detached from the supporting portion. To ensure that the magnifying device is securely held on the supporting portion, the snap-in pin may e.g. engage on recesses provided on the supporting portion. Preferably, the supporting portion is configured such that the fastening arm at least partially embraces the supporting portion. Special recesses on the supporting portion for engagement by the snap-in pins are not required.
Preferably, the fastening means comprises two snap-in arms of elastic configuration, each arm comprising a snap-in pin. This facilitates attachment of the magnifying device to and detachment of the magnifying device from the supporting portion.
In a particularly preferred embodiment the magnifying device comprises two magnifying means, each magnifying means being arranged in front of one eye. These are preferably two magnifying means which can be handled independently of each other. Said magnifying means may be of identical configuration and are individually attachable to the supporting portion. Thus the two magnifying means can be directly attached, independently of each other, to the supporting portion such that they are arranged in front of the respective eye. The ocular according to the invention is thus adjustable to the interpupillary distance of the individual users.
Each magnifying device comprises two lenses arranged in the optical path of the human eye. For focus adjustment the lenses are adapted to be displaced relative to each other. This displacement can be carried out by means of a rack and a focussing wheel. Further, an electrical focussing can be provided, wherein the distance between the two lenses is adjusted e. g. by a motor-driven screw-and-nut system. Electrical focussing offers the advantage that automatic focussing in the form of an autofocus system can be provided. When a user of the ocular according to the invention has a vision defect, this defect is usually compensated for by the lenses of the ocular so that, prior to using the autofocus system, the distance between the two lenses must be adjusted such that the vision defect is balanced out. Then continuous focussing using an autofocus system can be performed.
In another preferred embodiment the magnifying means are not attached but articulated to the supporting portion. This allows the magnifying means to be folded when the ocular is to be transported such that the ocular has a small transport size.
For secure fastening of the magnifying means to the frame or the supporting portion of the frame a reinforcing bar may additionally be provided, the bar extending from the magnifying means to the frame thus ensuring lateral stabilization of the magnifying means. The ends of the reinforcing bar are removably connected either with the frame or with the magnifying means such that, according to the embodiment, the magnifying means can be either detached or folded after removal of the reinforcing bar.
Preferably, the fastening means for the magnifying devices to be attached to the supporting portion are configured such that the magnifying devices can be attached to normal spectacles. In this case the magnifying means or the lens arranged nearer to the eye would be located between the eye and the lens of the normal spectacles. Further, it is possible to configure the fastening means of the magnifying device such that the two magnifying means are arranged in front of the lens of the normal spectacles. Arrangement of the lens of the normal spectacles between the two magnifying means offers the advantage that the spectacle frame is securely held on the human head and does not tilt due to the additional weight.
Another preferred embodiment solving the object of the present invention, i.e. to provide an easy-to-handle ocular, relates to a second pair of lenses attachable to normal spectacles. In this embodiment the ocular according to the invention comprises at least two lenses per optical path, i.e. at least two lenses are arranged in front of each eye. Further, the ocular comprises a frame having a holding portion for holding the ocular on the human head. This holding portion may be a normal spectacle frame. A first pair of lenses is connected with the holding portion of the frame, the pair of lenses comprising one lens per optical path such that one lens of the pair of lenses is arranged in front of each eye as in the case of normal spectacles. In front of the first pair of lenses a second pair of lenses also having one lens per optical path is arranged.
According to the invention the second pair of lenses is removably connected via fastening elements with the holding portion of the frame. Said fastening elements are arranged on the outside of the lenses of the second and the first pair of lenses. Since at least two fastening elements are provided and these elements are located on the outside of the pairs of lenses, said fastening elements are arranged at as large a distance as possible to each other. This ensures good stability of the connection between the second pair of lenses and the holding portion of the frame.
Further, another fastening element may be provided between the two lenses of the two pairs of lenses. Said fastening element connects the two bridges arranged between the lenses of a pair of lenses.
Preferably, the fastening elements are configured such that the distance between the two pairs of lenses is adjustable. Easy adjustment of the distance between the two pairs of lenses allows easy focussing of the magnified picture. Preferably, the fastening elements are fastened to the sidepieces of the frame such that they are adapted to be displaced. For this purpose the fastening elements may be configured such that they at least partially embrace the sidepieces of the frame. Due to the elasticity of the portions of the fastening elements embracing the sidepieces of the frame an adequate friction can be produced such that the second pair of lenses, relative to the first pair of lenses, can, on the one hand, be easily displaced by hand and, on the other hand, remains in the adjusted position when the ocular is taken off. Maladjustment of the distance between the two pairs of lenses due to slipping can be prevented by providing an additional fixing means, such as a screw or a snap-in means.
In a particularly preferred embodiment of the ocular according to the invention the frame comprises a drive unit and a focussing unit. The drive unit allows the distance between the two pairs of lenses to be automatically adjusted. The additionally provided focussing unit allows this adjustment to be effected automatically in such a way that the viewer always sees a sharply defined, i.e. automatically focussed, image.
As in the case of the preferred methods of connecting the magnifying device with the supporting portion described above, the fastening elements can, in the present embodiment, be configured e.g. with snap-in pins and similar parts.